What Must Come to Pass
by fearlessgoddess2
Summary: X-Files Crossover. Mulder calls on Sam and Dean when he finds himself out of his league.
1. Chapter 1

"_The Revelation of Jesus Christ, which God gave unto him, to shew unto his servants things which must shortly come to pass…._"

- Revelation 1:1-8

**This is about six months after Apocalyptic, no specific place in the timeline for that story, but I'll put this one after My Bloody Valentine since that's what I know of the plotline so far. And everyone should know that we're firmly in the Supernatural-verse, so there won't be any mention of aliens. :)**

**What Must Come to Pass**

Dean startled slightly out of his concentration, or rather what had turned into blank staring at the book in front of him, and let out a sigh as he dug his cell phone out of his jacket, raising it to his ear. "Ya?" he asked.

"_This is Special Agent Fox Mulder. Is this Dean?_"

Dean's eyebrows rose, glancing to Sam briefly across the library table, who was deep in research of his own. "Ah, yeah. What's going on?"

"_I got this number from Bobby. You said to call if anything seemed out of my league._"

"That I did," Dean responded. He got a sharp shushing noise from a librarian at the ongoing conversation, and received a glare as well when he looked over to meet her eyes. He gave her a wide, innocent smile, but somehow she was immune to his charms and simply pointed to a sign behind the desk that read _No Cell Phones._

"_Well, I think I've got something,_" Mulder spoke as Dean reluctantly got up from his seat. That jarred Sam from his focus and he looked up, a questioning look on his face at who was on the phone. Dean held up one finger to him as he left, tossing another smile to the librarian over his shoulder, this one slightly cockier, as he went out the automatic doors.

"Alright, give it to me," Dean said.

"_I'm in central Oklahoma right now. I've been here for a day or so with Scully looking into a large amount of deaths—._"

"Define 'a large amount,'" Dean interrupted, leaning against the brick wall of the library.

"_Ah…._" There was a rustling of papers. "_By my count so far we've got…214._"

Dean's spine straightened suddenly. "What the Hell?" he asked, eyes wide. "_Where_ are you, exactly?"

"_Chandler, Oklahoma._"

"Is that the CDC thing I heard about? I thought there had only been like five deaths and it was from swine flu?"

"_God, I wish it was the flu._"

"What did they die from?"

"_Some from yellow fever, some from malaria, small pox, cholera, a bunch of diseases thought to be eradicated or widely vaccinated against, especially in the US. And some victims were infected with several of them._"

"Holy shit…" Dean muttered to himself, his eyes narrowed tightly. He pursed his lips. "I'm assuming the CDC's got smoke coming out of its ears."

"_Yeah. They're chasing their tails because they've been trying to contain it, quarantine the infected, but it just keeps spreading_," Mulder explained. "_They can't figure out how._"

"Okay, that's weird, but this does seem like a straightforward CDC problem," Dean told him. "Biological weapons attack or something. Why call me?"

"_Because each of the deceased had residue of something else in their bloodstream besides the disease they died from and they can't find a reasonable way to account for it._" Dean's heart seemed to sink into his chest."_I don't know if you've seen this before—._"

"Sulfur," Dean breathed, leaning back against the wall and shutting his eyes, massaging his forehead. "Damnit."

Mulder was silent for a moment. "_I guess I called the right guy._"

"Yeah, you did," he grumbled. Dean paused, chewing on the inside of his cheek. "Listen, are any of the victims acting…psychotic?"

"…_What?_" Mulder asked, puzzled.

"The infected. Are they becoming violent?"

"_Ah, no. No, they're just getting sick and…dying._"

Dean paused again. "All right. Hey, how come I haven't heard that the plague is spreading through central Oklahoma?" he asked. "On the news or whatever?"

"_Why do you think?_" Mulder asked tightly.

"Panic, right, but…I guess what I meant was _how_ have I not heard anything?" Dean asked. "How is this being kept under wraps?"

Mulder sighed, rustling the phone line with static. "_That's another reason I called you. I'm not sure how much longer we can keep this quiet. Honestly I was hoping this was up your alley cause that means we don't have all the pieces of the puzzle and explains why we're getting nowhere._"

Dean snorted. "Trust me, you really don't. All right, Sam and I'll take off right now. We should make it there in…" Dean checked his watch, "…like twelve hours, if we trade off driving. Where should we stop? I want to park us a good amount from this thing."

"_Outskirts of Oklahoma City should be fine_," Mulder replied. "_That's where I'm at._"

"Yeah, by the way, how is it this is your jurisdiction, if you don't mind me asking?" Dean asked, half his mouth sliding up in a smile.

"_Ah, it's not really. I'm technically here with Scully working on a cold case that I just got a fresh tip on._"

Dean nodded. "Nice. I'll call you when we're close. Call me with any updates."

"_I will. Oh, and Dean?_" Mulder asked.

"Ya?"

"_I want to be honest with you. After we ran into each other a while ago I did some checking up on you and your brother. Did some research on what you guys called 'hunting'. Once I got the last name Winchester it was pretty easy to find your background. And I, ah, talked to a few people who were reluctant or downright stonewalling when I brought you up._"

"Yeah, I know," Dean replied simply.

Mulder paused. "_You know?_"

Dean smiled slightly. "Well, say your friends got a call from some strange guy asking about you. What are they gonna do?"

"_They told you._"

"Soon as they hung up with you, I got a call," Dean said with a nod. "So thanks for the honesty, but if I didn't think you were on the up and up, I wouldn't have told Bobby to give you my number if you ever called him."

"_I see,_" Mulder murmured. "_Can I ask what swayed you toward trusting me?_"

"Well, mostly because of your history in the FBI, Special Agent Spooky Mulder."

Mulder chuckled. "_Did some research of your own, huh?_"

"I have to admit, I was intrigued at the whole FBI-hunter thing from the get-go," Dean replied. "I think you've seen enough to know that what my brother and I do is the real deal, so as long as you're not a moron that means you'll back us up."

"_Glad to hear my resume speaks for itself_."

"It sure does. See you tomorrow, Mulder."


	2. Chapter 2

Chapter 2:

"Honestly, there's a lot of things it could be," Sam said, flipping through pages of research he'd printed from his laptop as well as the occasional reference to John's journal. "Ekimmu, vaettir, manananggal, lamashtu, ajatar—."

"Think of the teasing those guys got in middle school," Dean muttered.

Sam sighed, running a hand over his face as he leaned back in the motel room chair. "It's just that I've never heard of something like this, this many people dying. And so quickly. Actually, those are just some of the creatures that can spread disease. There was sulfur found also, which means it's demonic, and that eliminates quite a few of them. When did Mulder say the first victim got sick?"

"Last Thursday. Four days ago," Dean told him. "She was dead within twenty-four hours."

"And the fact that they can't seem to quarantine it, that's got to mean that this thing is spreading from a carrier," Sam added. "Whatever started this is still roaming free and able to spread the infections."

"Well, how many of the creatures you came up with can look human?" Dean asked. "Or at least could slip around unnoticed? Cause I doubt it'd be able to lurk around with law enforcement cordoning off everything if it was four feet tall, green, and had horns or something."

Sam nodded, looking over his list. "Right. Ah…that leaves an ekimmu, vaettir, or ker as the most likely suspects." He paused. "Unless this might be…something we need to call Cas about."

"Let's not go there 'til we have to," Dean grumbled.

"No argument here. So how open do you think Mulder would be to helping us get in as CDC?" Sam asked, looking up to his brother.

"You mean full-on hazmat suits?"

"Yeah."

"We'd have to ask."

"Then we'll ask him," Sam said, glancing at the clock, which read 10:30 AM. "We need to call and tell him we're here anyway."

"Alright. I'll ask if he can bring over stuff about the investigation so far also," Dean responded, taking his cell from his jacket and dialing Mulder's number. He waited a moment as it rang.

"_Mulder._"

"Hey, it's Dean."

"_You guys all settled?_" Mulder asked.

"Yeah, we got here at like 3:00 AM so I figured we'd just wait 'til morning to call. You can come on over if you want. It'd be good if you could bring anything you've uncovered so far in the investigation," Dean told him. "Anything about the sulfur, the autopsy reports, etcetera."

"_Ah…maybe you guys want to come to me, then?_" Mulder suggested. "_I've sort of got a system here and…there's a lot of information piled up around my room._"

Dean smirked slightly, familiar with the mountains of research that could pile up on hunts. "That's fine. Where're you at?"

"_Motel 6 on Gregorson Drive. Room 208._"

"'Kay. By the way, is Scully there?" he asked, grabbing his keys as Sam closed his laptop and put it in his backpack.

"_She's actually been spending a lot of her time on the medical side of this,_" Mulder replied, "_so she's in the thick of it right now. Been working in the labs trying to figure out the viruses, though they haven't been making much headway. Left about fifteen minutes ago._"

"So she's gone for a while?" Dean asked.

"_Yeah. And I didn't tell her I called you guys. I wanted to make sure that was good by you first. But just so you know, once I turned out to be right on what happened with the skinwalker six months ago, added with the fact that you guys brought her back to me and patched her up, she trusted me on letting you guys take off._"

"That's good to know. She in on any of the research you did on us?" Dean asked as Sam closed and locked the door behind them.

Mulder snorted slightly. "_You mean on your last names and the record that comes with it? No. I'm not sure how keen she'd be on letting that slide._"

Dean smiled tiredly. "Alright. We're taking off, so we'll be there soon."

"Nice," Dean sighed, sliding his eyes around Mulder's motel room as they were let inside.

There were piles of papers, folders, photographs, and the occasional pen strewn around the room, mostly likely in some particular order, just not one that was discernible to Sam and Dean. Many more photographs and papers were pinned up on the wall, with more of a visible pattern to it, several papers that were stapled together pinned with a photograph of the victim. That went around each of the walls, presumably in order of the deaths, for each deceased. There were also several fast food bags around the room, since the small wastebasket had easily been filled with a couple of them.

"I cleared the chairs for you guys to sit over there," Mulder told him as he shut the door. "I know it looks like a tornado ripped through this place, but—."

"Trust me, we've been here," Sam interrupted him, shifting his backpack on his shoulder as he looked over the walls. "Especially with cases like this, you don't know what will end up being useful, so you just stockpile everything. And computers can't do everything."

Mulder smiled slightly. "I suppose you guys are familiar with this sight. Scully looked at this place and asked if I was robbed. Either that or lost my mind somewhere in this mess."

Dean snorted. "The bar for insanity with us is pretty high."

"Guess you've got to keep an open mind in your job?" Mulder asked.

"You've got no idea," Dean muttered.

"Well, just start us off from patient zero," Sam said. "Let's see where it originated, go from there."

"Ah, deductive reasoning tells us the first one was Leslie Parker, female, twenty-eight years old," Mulder told him, motioning to the first file on the wall and walking over to it. "Small pox and yellow fever were found in her system. Treatment didn't help. She was dead within a day. It goes from there," he said, motioning to the right along the wall.

Sam looked at the file, flipping through the pages on the wall after glancing at the picture of the deceased young woman. "Walk us through what the CDC has put into effect?" he asked.

"It was originally classified as Category B, but was elevated to Category A when it kept getting outside the quarantine area. This is day four and I got word this morning that the intensity of this thing is finally getting around since they started evacuations to help isolate the infected," Mulder told them as Sam continued to skim the patient files. "Apparently the media should be all over it by this evening's news."

"Great," Dean muttered.

"They're considering this bioterrorism, if only because they can't seem to stop it," Mulder continued. "Nobody has claimed responsibility for it, which we won't be able to count on as authentic once word gets out to the public. We'll probably be having groups left and right take credit once that happens. Once the CDC established the number of viruses that were spreading, their response was to lock down everything, get everyone tested and set up quarantines. They tried to set up multiple quarantines for the different viruses, but eventually it became too much to separate. There were too many different combinations of them in people. And since they can't seem to cure anyone, it seems to be a death sentence anyway."

"What have they find out about the viruses, exactly?" Sam asked, turning to Mulder. "Anything that distinguishes them from normal viruses?"

"From a scientific standpoint, aside from the sulfur present, no," Mulder responded. "The viruses appear to be very standard. Dean said you've encountered the sulfur thing before. What's that about?"

"It's complicated. Do you have photographs of the viruses in the bloodstream?" Sam asked. "From the labs, blown up so the morphology's discernible?"

"Yeah," Mulder replied with a nod, going over to his bed and moving aside a few folders before finding the one he was looking for, taking out some photographs. "They're labeled on the back. That's smallpox," he said as he handed over the photos, "zoomed in a few times in those ones."

"Okay," Sam murmured, pausing to look at the first photo, then the second, then the third, before showing them to Dean. "I remember looking at the sulfur under the doc's microscope back in River Grove. The sulfur was scattered around about…one molecule to every fifteen blood cells or so, I think, and about the size of one. This is different. Look at the sulfur here. Much more sparing and much smaller. Sulfur in the human body is rarely in its pure form, and definitely not just floating through the bloodstream. That's why it's obvious something's weird here."

"And she never found any actual trace of the virus, only the sulfur, right?" Dean asked, taking the pictures to examine them.

"Right. Here we have actual, identifiable viruses."

"Not to mention the infected aren't getting homicidal," Dean added.

"What's River Grove?" Mulder asked, his eyes narrowed.

Sam sighed, running a hand through his hair anxiously. "Ah…you ever hear of Roanoke? Lost colony?"

"Yeah, whole community that disappeared a few centuries ago when North America was first getting settled," he answered.

"About three years ago in River Grove, Oregon, we came up with a solid theory on what happened to them," Sam muttered.

Three sets of eyes darted to the door suddenly as a key rattled in it and it swung open. "I realized I must have left some of my notes—." Scully stopped at the sight of Sam and Dean, staring at them blankly for a moment before looking to Mulder, narrowing her eyes at him. "Well. Sorry, I…didn't realize we had company."


	3. Chapter 3

Chapter 3:

"And so you're telling me we're fighting this same virus?" Scully asked, eyes wide. "That we're up against a _demonic_ virus?"

"I don't think it's the same virus," Sam told her. "Like I said, the virus in River Grove wasn't visible aside from the sulfuric residue. And it only spread through blood to blood contact."

"Plus the infected get the little side effect of going nuts," Dean added. "We're not seeing that here."

Scully let out a long, tired breath. "This is unbelievable," she muttered.

"Like…literally unbelievable or…frustrating unbelievable?" Dean asked.

"A little of both," Scully responded.

"Even after the skinwalker in Minnesota?" Dean asked, folding his arms. "You're still putting up a wall of logic and science?"

"I have to. It's my job," Scully told him with a glare.

"No, your job is to _do _the science," he countered. "It's not to shoot down every other theory."

"Look, we all want the same thing," Sam interrupted. "We want to stop these diseases. That's why we're here."

"All right," Scully replied. "Fine. This is your theory. Prove it, then I'll get on board."

Sam sighed and nodded. "Fair enough. Ah…has the CDC made any progress in the analysis of the viruses and possible antidotes or vaccinations?"

"None," Scully responded, shaking her head. "It's been established that the viruses are standard, early on being easily identified, and it cannot be determined why treatments are ineffective or how it keeps spreading beyond the quarantines because it isn't airborne."

"Have you considered a carrier as a possibility?" Sam asked.

"For _all_ of the viruses?" Scully asked, her eyes widening. "Highly unlikely. More plausible is someone physically spreading the viruses. Bioterrorism."

"And the sulfur?" Dean asked, cocking an eyebrow.

"We don't know how the sulfuric residue gets into the bloodstream," she told him, albeit slightly reluctantly.

"No theories?" he asked dryly. "From anyone?"

"Nothing plausible," Scully snapped.

"Okay, this is _really _not helpful," Sam told them firmly. "Scully, has there been anything else suspicious going on in the area?"

"Suspicious?" she echoed.

"Anything out of the ordinary," he said.

Scully paused before shaking her head. "I don't think so."

"Mulder? Anything?" Dean asked, glancing over to the agent.

"Nothing more than what I told you, sorry," he responded with a shake of his head.

"Could I see the autopsy photos for Leslie Parker?" Sam tried.

"Sure thing," Mulder replied, going over to a bunch of papers on the table, sifting through for a specific folder and giving them to Sam, as Dean continued to look over the files on the wall. Sam took the autopsy photos and sat down at the table, opening the folder and looking through them.

"Mulder, would you care to explain why you failed to mention to me that you were calling these two in to consult?" Scully asked, motioning to the boys in frustration. "I really don't appreciate it."

"Because I know you don't trust that their information is good," Mulder replied.

"No, I don't trust that The Lone Gunmen's information is good. These two, I don't _know_," Scully corrected him. "Come to think of it, _you_ don't know them either."

"He's still reasonable enough to give us a chance and listen to our side of it," Dean said, narrowing his eyes and looking over to her. "There are more things and heaven and Earth, right? I mean, come on, you can't just trust us a little, even after what we did for you?"

"Firstly, that's about how there's more to some things than meets the eye," Scully told him immediately. "Not supernatural explanations. Secondly, I just don't know anything about you, so I'm not going to trust you right away. Don't you think that's fair?"

"Sure it's fair. So as long as—."

"Dean," Sam spoke tightly, his voice low and serious.

Dean immediately stopped at his brother's tone and looked over at him. "What?"

"I think we need to call Cas."

"You're kidding," he grumbled, walking over to take a look at the photo in Sam's hand.

Sam stood up and handed it to him, motioning to a brand on the young woman's hand. "Look familiar?" he murmured.

Dean gnashed his teeth together. "Son of a bitch," he whispered.

"What?" Scully asked. Dean ignored her, letting out a sigh, and handed the photo back to Sam as he dug out his cell phone from his jacket.

"What'd you see?" Mulder asked, walking over to Sam.

"The brand on her right hand," Sam told him, pointing to it.

"It was noted in the autopsy report as a tattoo," Mulder told him, his forehead creasing worriedly. "Why? What's it stand for?"

"It's complicated," Sam muttered, turning his gaze back to the photo and bringing it closer to his eyes to examine it.

"Hey, Cas, we got something for you," Dean spoke into his phone.

"Everything's complicated with you guys, huh?" Mulder asked Sam, raising an eyebrow. Sam just remained quiet, grimacing.

"_I sense there are others in your presence. Should I knock at the door first?_" Castiel asked Dean.

"Should you—? No," Dean snapped, his eyes widening, prompting startled gazes from Scully and Mulder. He calmed his tone and turned to face away from them, walking toward the bathroom. "I just called to talk to you."

"_About what?_"

"Sam and I are in Oklahoma right now on a job. There've been over 200 deaths so far and—."

"That's wrong," Scully spoke up suddenly.

The others looked to her, surprised. "How's that?" Dean asked, moving the phone from his mouth.

"When I called the lab this morning telling them I was going to be late…they said since I was there yesterday another epicenter of disease has emerged outside the quarantine. There've been…at least two hundred more deaths," she said quietly.

"Shit," Dean muttered. He moved the phone back to his mouth. "Make that over 400. And we found a brand on one of the victims that looks like a sigil from Pestilence, the horseman."

Castiel paused. "_Would it be possible to meet to verify it?_"

"Ah, yeah, lemme call you in a bit," Dean told him. He hung up the phone, turning back to the two agents. "We're gonna need to borrow the photo there. We've gotta…head to a library, scan it, talk to a friend of ours who's a, ah, expert in this kinda stuff."

Scully scowled slightly, but smothered it quickly, letting out a sigh. "Fine. You know what? You do whatever you two need to do. If you come up with an answer to what's going on and a way to help stop this thing…." She paused, waving at them dismissively, tiredly. "I'm not going to argue with it."

Sam smiled tightly at her. "Thanks. We'll call you guys with any news."


	4. Chapter 4

Chapter 4:

Dean took his cell from his pocket as he walked into the motel room, dialing Castiel's number. "Yeah, we're at a motel right now. You can pop in. Super 8 in Carlisle, Oklahoma, room 15." As expected, a subtle flutter of wings sounded as barely a warning for Castiel's jack-in-the-box-like appearance directly to Dean's right, and he hardly managed to keep himself from startling. He took the photo out from his jacket, handing it over to the angel. "The brand right there," he said, pointing to it as Sam shut the door. "Was noted in autopsy as a tattoo, but—."

"It's the brand of Pestilence," Castiel said, his tone grave. He looked back to Dean. "When did her death occur?"

"Four days ago, Thursday, 3:41 AM," Sam answered.

"And over 400 more deaths since," Dean repeated, folding the photo back up and putting it in his jacket. "Look, Cas…I've got to ask." He let out a rough sigh, ruffling his hair anxiously. "The other horsemen we had to deal with…the rising of the witnesses…Samhain…all this stuff…I mean…aren't there _any _other angels out there besides you rooting for our side?"

Castiel gazed evenly at Dean for a long moment, unsure of where his line of thought was going, and shook his head. "I have no idea."

"So is it just gonna be us?" Dean asked, anger edging into his tone. "Always just us? We're going up against the _devil _here, the damn extinction of the human race and we've got no help on this. Mulder told me there was sulfur found in their blood and…. I mean, this could've been the Croatoan virus, and we've still got no backup. We need _help_. So all the angels are up there going, oh well, too bad for these mud monkeys, let's let Lucifer wipe 'em out and see what the big guy upstairs cooks up next?"

"Do you think that I am even in any sort of communication with other angels?" Castiel barked at Dean. Dean blinked, not accustomed to an angry reaction from the angel. "I am in _exile_, Dean, a renegade as far as my superiors are concerned, with a fraction of power that I have had at my disposal for longer than you can comprehend. This is not one of your…your _movies_ where I use an untraceable cell phone to contact my brothers and sisters to find us more allies. _I am in hiding_," he said, accentuating each word forcefully, "because I disobeyed direct orders. Even if I were to make contact with one I trusted, we do not know how many are working with Zachariah. And I cannot defeat Heaven. _We_…cannot defeat Heaven. In that sense it would be as if you were to walk into the headquarters of your FBI and attempt to defeat _them_. This, here," he said, waving to their surroundings, "_this_ is all we can do." He stared at Dean for a moment, and then looked away briefly before meeting his gaze again. "We have no help. I assumed you understood that fact by now."

At that, with a brush of air harsher than normal, Castiel disappeared.

"Goddamnit," Dean muttered, looking around the room, though he knew he wouldn't find Castiel. He walked over to the table, falling harshly into a chair, and banged his fists on the table. He was silent for a long moment. "Touchy subject, I guess."

"Maybe you should try _not _alienating the best ally we have right now," Sam shot at his brother, going over to his bed as he took out his laptop.

"Dude, I'm just pissed," Dean snapped. "I think I've got the right to be."

"But why take it out on Cas?" Sam exclaimed.

"I wasn't taking it out on him! I was just—." Dean sighed, letting his head fall into his hands. He shook his head and leaned back into the chair, bumping the table a few times with his fist.

"He's _alone_, Dean," Sam said quietly. "More alone than…he's ever been. More than we can comprehend, I'm sure. He can't even find God, the one thing he's always believed in. You take away the one thing someone believes in…. I'm impressed he's doing as well as he is."

"Yeah," Dean murmured. He pursed his lips thoughtfully. "It's just…he's an angel. You know?" he asked, looking over to his brother intensely. "I mean…Christ, if he can be taken down by loneliness, what chance in Hell do we have?"

Sam stared at his brother tiredly for a long moment before he sighed and shook his head. "One problem at a time, man," he muttered. "Apocalypse first. Then we deal with the emotional angel."

"Right," Dean grunted. He paused for a long moment before he clapped his hands, rubbing them together. "Alright. You get your geek on. I'm gonna call Bobby and see if he's got some info on this thing and…we'll try to pull some sort of plan out of our asses."

"But if it's demonic, it could work," Sam stressed.

Dean nodded slowly. "Yeah, but firstly, Special Agent Logic won't go for it, and secondly, it doesn't solve the actual problem of the demon spreading the diseases."

"We've got no leads on how to stop this thing so far, so we may as well try this," Sam said firmly. He folded up the piece of paper in his hand and held it out to Dean with a slight glare until he took it.

"Fine," Dean muttered, putting it in his jacket. "You're right, it's as good a plan as any. You keep with the research and mapmaking and I'll go tell Mulder we're gonna use magic to fix this."

Sam smirked slightly as he sat back down at his computer, taking the pen from behind his ear and chewing slightly on the end as he stared at the information on the screen.

The area swam with a sort of organized chaos as Scully watched another patient on a gurney, this one a twelve-year-old boy, be handed off to an ER nurse. Everyone was in full-body HAZMAT suits, close-fitting so they could still do their jobs. Although their jobs had turned into regularly flying the constant onslaught of infected into the quarantine and pumping them full of drugs that they knew wouldn't cure them.

Scully's Bluetooth beeped in her ear, signifying a call, and she raised her hand to press the button on the side through the suit. "Scully."

"_It's me,_" Mulder told her. "_I've got something for you to try and I need you to not dismiss it. Can you do that?_"

Scully narrowed her eyes. "What are you talking about?"

"_It isn't dangerous, you have nothing to lose and everything to gain. Promise me that you will try this._"

"My God, Mulder, we're up to our elbows in suffering, dying people with no end in sight. I'll try anything you want, just give me _something_," she snapped.

"_I want you to administer the treatments you're giving the patients with one more ingredient. Holy water._"

Scully blinked, her eyes widening, and then narrowed back into frustration. "Are you joking?" she exclaimed.

"_Scully,_" he said firmly, "_try this, okay? Even the boys don't know if it'll work, but what do we have to lose?_"

Scully consciously lowered her voice, even though nobody was paying attention to her and even if they were there was too much chatter to hear her, especially through her suit. "Where would I even get holy water?" she asked.

"_I've got the rite. You can bless it yourself. You're wearing your cross, right? The gold one?_"

Scully's hand involuntarily rose to rest over where her necklace rested on her chest and she swallowed tightly. "Yes, I'm wearing it."

"_Can you get some sterile water for this and get someplace private?_"

Scully let out a long sigh, closing her eyes for a long moment before nodding. "Fine. Just…just a second."

Five minutes of dodging nurses and doctors and scientists later, Scully was in an empty lab room with two liters of sterile water and her cross, which she had also sterilized. "All right," she muttered. "Go ahead." Mulder carefully recited the rite and Scully repeated it. "_Exorcizo te, creatura aquæ, in nomine Dei Patris omnipotentis, et in nomine Jesu Christi, Filii ejus Domini nostri, et in virtute Spiritus Sancti: ut fias aqua exorcizata ad effugandam omnem potestatem inimici, et ipsum inimicum eradicare et explantare valeas cum angelis suis apostaticis, per virtutem ejusdem Domini nostri Jesu Christ: qui venturus est judicare vivos et mortuos et sæculum per ignem._"

Scully dropped her necklace into the beaker. "Okay. I…now have holy water."

"_Can you administer it without anyone noticing?_" Mulder asked.

"Ah…I guess I can use a syringe to put it in the saline solution of their IVs," she told him. "Nobody'll know the difference. How much?"

"_They said about 10 ml will be adequate. Call me if this goes somewhere._"

"Will do." Scully pressed the button on her Bluetooth, letting out another sigh, before she went into a nearby drawer. She took out a handful of plastic-wrapped syringes and started filling them with the water.


	5. Chapter 5

Chapter 5:

"Pulse is 140 and thready, BP's 50/30."

"What's this one?"

"Cholera."

Scully walked quickly by the gurney's side to keep up with it as it was wheeled down the long hallway and into a large room, then put at the end of the row of many others. She went through her normal procedure of taking blood, giving it to the lab tech that was waiting for it, and setting up the IV drip with rehydration salts, an injection of doxycycline. In the hectic environment no one noticed that when she should have been finished that she also injected 10 ml of holy water into the IV. And then she waited.

Scully wasn't sure what she expected to happen, if maybe the fourteen-year-old girl was going to sit up, her head would spin around, and she would spew pea soup all over her sheets, but whatever she was expecting it didn't happen. The young girl remained unconscious, not moving. After a few long moments, Scully slowly walked away.

It was only three hours later when word of the girl's improvement spread that Scully realized that she needed dismiss any doubts she had of the new treatment. And she started to inject the holy water into each patient's IV.

Of course, it was one thing to inject it once or twice. A constant addition of an injection was bound to gain attention eventually.

"You _are_ doing something else," snapped a voice behind Scully, startling her into turning around once she'd injected a syringe of holy water into the IV of a middle-aged man.

Scully stared wide-eyed at another nurse about her age who was glaring at her with heavy suspicion and worry. "It's just water," Scully told her.

"I can't know that. Whatever that is, it's not a standard injection. Security to 2B, south entrance!" she barked into her walkie talkie.

"There was nothing in it but water!" Scully repeated.

"Give me the syringe," the nurse shot back, holding out her hand, "and I'll find out. The analysis comes back as H20, we'll talk."

Scully paused and handed over the syringe. "When it comes back clean and you believe me, you're going to have to listen to me. As crazy as what I say is going to sound, what's in my syringes is why people are getting better."

The nurse narrowed her eyes at Scully for a long moment before nodding. "Fine. But you're waiting with security until I verify it."

"_And how are we doing at cutting the head off the snake?_" Mulder asked.

"Working on finding a nice sharp machete," Dean replied, looking over the papers that his brother had printed out from Bobby. "Look, I'm glad to hear it worked, but I've got to go. Call me if something else happens."

"_All right._"

Dean tossed his phone onto the bedside table, looking back to Sam. "That metaphor isn't really accurate. We've got the machete to cut the head off the snake, we just…don't know where the snake is."

"Or how to find it," Sam continued. "Or how powerful it is. Or even if the Colt is going to work against it; that's just our best bet. Dean, the only way we're going to gain any progress on this thing is the old fashioned way."

"Go in and track it. I know," Dean muttered. "Okay. Show me our trail," he said, getting up and walking over to Sam. He looked over the map of Chandler that his younger brother had put up on the wall and had been putting tacks into, hooking strings from one to the other, for hours.

"It's spread along this path, the red string, basically," Sam told him. "It just looks like a random path when it comes to traditional navigation. I started with Leslie and worked my way forward, but obviously a problem I ran into was that symptoms can take hours to manifest, so I needed to get a good idea of where people had been in the hours before they started to show symptoms."

"Did that work?" Dean asked, raising an eyebrow.

"To some extent. It was like…connecting a family tree. When I listed the places they'd been and at what time, many of them overlapped. Not just like three people had been at the same restaurant and gotten it, though; they left and went somewhere else and spread it _there_, again and again for a few different places."

"But you were able to figure out where Pestilence had been by backtracking to the first place they'd been."

"Right," Sam said with a nod. "The most help was when the CDC tried to quarantine it and it failed. The next outbreak was where it had gone next, and that was a separate family tree…sort of."

"'Sort of' because when the first tree's family members spread it, it started to overlap."

"Exactly," Sam said with a slight smile of relief that he was able to explain it. "Anyway, lots of math that I never thought I would use again later, I've got this." He ran his finger down the red string. "It's pretty straightforward, actually. Every time the CDC quarantines the area—."

"It starts up again right outside the quarantine area," Dean muttered. "Son of a bitch is playing with us."

"But it's been a few days," Sam told him. "Eventually the demon won't even be necessary anymore, and it knows that. As soon as panic sets in, it'll only take a few people driving a hundred miles to spread it, and then it's out there. We can't hunt a virus."

Dean swallowed tightly, knowing that technically that statement was wrong. "All right. The last quarantine expansion was out to there," he said, pointing to the circle Sam had drawn, "this morning, so where do you think it's at right now?"

"Best guess?" Sam asked with grimace. "Uh…." He looked at the area and took a pencil from behind his ear, sliding it around in an oval around a few streets. "Populated area. Same direction it's been going."

"All right. We gear up with one EMF each, holy water, and the Colt, and…find this thing and kill it," Dean stated.

Sam shook his head as he picked up his jacket from the back of his chair and slung it on. "Great plan. Wish I thought of it."

Dean scowled at his brother as he grabbed the car keys from the dresser and they headed out the door.

It was two hours of walking around the area that Sam had hypothesized the demon would strike in next, and then another hour of expanding the search area, before Dean's cell phone got a call.

"Ya," he answered, keeping one EMF meter earbud in his ear.

"_Dean?_"

Dean narrowed his eyes at the worried voice. "Scully? What's going on?"

"_I-I'm not sure. I was caught using the holy water but since it was working and it was just water the others agreed to keep using it, but that was an hour ago,_" she told him. "_Patients have been getting better, but we're having troubles._"

"What kind of troubles?" Dean asked, motioning to Sam to turn around to head back toward the car.

"_It's like someone's sabotaging the efforts. The electrical system is having some serious problems, machines are hiccupping and lights are going out—._"

Dean picked up his pace to a run as he interrupted her and Sam did as well. "Okay, Scully, listen to me. I need you to go get some of the holy water and keep it on you in a water bottle, all right? It can be used as a weapon against the demon if you run into it. It burns it like acid."

"_What—? Run into it?_" she exclaimed. "_It's here?_"

"Yeah, I think so."

"_Wh-what's it look like?_"

"It'll just look like a person because that's what it is," he told her. "It's not a monster with horns. It'll be possessing someone."

"_You mean it could be anyone?_"

"That's what I mean. Pay attention and see if you can pick up on someone not acting like themselves, in any way. If you think you know who it is, or just in case, if you say Christo, their eyes will turn black."

"_Great. Fine. How long until you get here?_" she asked loudly.

"Not long," Dean responded, stumbling to a stop outside the Impala and quickly getting inside, getting his keys from his jacket. "Call Mulder. Tell him what's going on. And get that holy water _now_, okay?"

"_Okay._"

Scully hung up and Dean shoved the phone back into his jacket as he pulled the Impala out onto the street, burning rubber as he did so.


	6. Chapter 6

Chapter 6:

Scully's chest was tight with anxiety, her senses on high alert for anything out of the ordinary as she walked down the hallway ten minutes later, restlessly awaiting the arrival of the cavalry. _Anyone. It could be anyone…. _She took in and let out a deep breath, trying to remain composed, as she watched the people around her doing their jobs. Scully walked hurriedly down the hallway as other nurses and doctors darted past her, getting to the front desk and leaning over to speak to the woman there. "Are they making any progress on the electrical failures?"

The woman grimaced and shook her head. "No idea what's causing it. And my computer's been down for the past fifteen minutes, Agent Scully. Every time it tries to restart, the electricity will hiccup again," she said, throwing her hands up in frustration. "They're down in the basement trying to figure it out, but I haven't heard anything."

"Okay," Scully sighed. She went down several winding hallways, took the stairs down two floors, following instructions to get to the basement's electrical system, where numerous people were working on laptops hooked up to several things in the room and others were looking over the circuits.

"Any idea what's going on?" Scully asked, looking around at them. "The nurses upstairs are getting worried."

"It's got to be something from the main grid," one of the young men spoke, looking up from his computer. "But they say everything's fine on their end. We're just fluctuating." Scully pursed her lips anxiously, shifting on her feet.

"The best thing you can do is head back upstairs and try to help keep the nurses calm," said Nathan, one of the electricians.

"All right. Thanks, Nathan." Scully headed back down the hallway and up the stairs, still trying to pick up on any clues that someone around her was possessed. _It's up to me. It could be anyone. _It turned out she didn't need to worry about finding the demon, however.

It found her.

Heading back into the lab and into the empty office that had been deemed hers to make a call to Sam and Dean and ask when exactly they were getting there, the door was stopped as Scully tried to close it. Her eyes only had enough time to narrowed in confusion and recognize that a hand had grabbed the door before it swung open. A punch was thrown into her stomach that propelled her backwards and into the wall, crumpling to the floor, and the door was closed and locked.

Scully gasped from the pain, trying to shove herself up to her feet, but the man who had entered, whom she recognized as one of the doctors — _Dr. Anderson _— tore his hood off, tossing it aside. He grabbed her by the throat and ripped her hood off as well, staring into her eyes as it shoved her against the wall. "No worries. You won't live to die from any of the diseases," it told her evenly, his eyes clouding over with blackness. Scully pulled desperately at the arm that held her, kicking at her attacker, but it barely reacted, simply immobilizing her with a firm arm across her chest, pushing her into the wall.

"Suppose you know what I am. You've been doing your damndest in this hospital to destroy all my hard work spreading these lovely viruses. So you're a hunter?" it growled.

Scully shook her head furiously. "No," she choked out. It eased up on the grip it had on her neck and she wheezed in and out. "No, I'm not, I swear."

"Just FBI?" it asked skeptically. "Then how'd you know to try holy water in the IVs?"

Scully flew the water bottle up at the demon's face, exploding into a sizzling mist, and the demon cried out, stumbling backwards. Scully attempted to dart around it, but as she got to the door it grabbed her by the arm and threw her across the room and into a file cabinet with a bang. The holy water dropped to the floor, spilling uselessly across it, as the demon let out a snarl, gathering itself before it went over to her and hoisted her up, shoving her even more harshly against the wall, its arm across her shoulders and other hand gripping her throat. "Bitch," it spat. "_How_ did you know about the holy water?"

Scully grimaced at the heavy nothingness in its inky eyes mere inches from hers, choking for air, but then swallowed hard and set her jaw. Demon or not, there was no way she was going to cooperate with the thing standing in front of her. She knew that she needed to bide her time until the boys got there or it would take off and they'd never be able to stop the viruses.

Staring at her intensely, the serious expression on the demon's face shifted into a frightening smirk as it realized she was clamming up. "You've got help, don't you? Someone on the outside pulling the strings?" it muttered. Removing the arm across her chest, it slipped a scalpel out from its jacket, holding it close to her face, causing her to resume her struggling against its iron-strong force. "How about I take an eye?" it asked softly. "Think that'll help you remember? Or should I just start cutting?"

Scully cried out as the scalpel was jabbed into her arm and twisted before it was yanked out. "Who's _helping_ you?" it growled.

Suddenly, its expression twitched in confusion as the P.A. system squealed once before a voice came across it. "_Exorcizamus te, omnis immundus spiritus, _

_omnis satanica potestas_—."

The demon jerked back from Scully, letting her collapse to the ground, narrowing its eyes and letting out a furious growl. Scully reached into one of her pockets and took out a syringe of holy water, yanking the cap off with her teeth as the demon turned to bolt out of the room, leaping at it and plunging the needle into its back. It cried out, stumbling forward, and clawed at its back as if it could grasp at the holy water and get it out of its bloodstream.

"_Ergo, draco maledicte et omnis legio diabolica, adjuramus—_."

The demon's face contorted in pain as its breath caught in its throat and tore out as a cry of pain, collapsing to the ground. Scully slid out another holy water syringe and kicked the demon in the stomach, causing it to curl into a fetal position, and Scully jabbed the syringe into its neck, depressing the plunger and sending more of the poison through its system.

"—_invocato a nobis sancto et terribili nomine—._"

Scully's breath came quickly as she frantically searched her jacket for another syringe and came up empty. She looked over to the bottle of water that had mostly spilled across the floor and quickly went over to it, sticking the syringe into it and pulling the water in, keeping one eye on the demon.

"_Ut Ecclesiam tuam secura tibi_—."

As Scully got hurriedly to her feet and darted over to the demon, it kicked out at her, sending her sprawling to the ground, but she realized it was starting to almost go into a seizure.

"—_te rogamus, audi nos_!"

Scully stumbled frantically back from the demon, sliding down the wall as if to get away from the black smoke that expelled from its mouth in a scream, pouring up toward the ceiling. She stared at it in shock, eyes wide, as it collected in a dark mass and disappeared into a puff of fire and ash. Her breathing still rough, Scully suddenly found the room heavy with silence and she swallowed tightly, wincing at the throbbing pain in her arm.

There suddenly was a loud knock at the door and the doorknob rattled. "Hey, what's going on in there?" called a voice.

Suddenly, the man sprawled on her floor coughed, causing her to jump in fear, and his eyes widened as he struggling backwards along the ground, looking around in a panic. "Wh-what—?" He swallowed as he looked himself over and glanced over to Scully shakily. "You…."

"Dr. Anderson?" she asked uneasily as the knocking became more urgent.

"Y-Your arm," he stammered.

Scully's cell phone suddenly rang in her pocket and she fumbled to get it out. "Yeah?" she breathed.

"_Scully, it's Dean. Where are you?_"

"First floor, room 232," she said.

"_We'll be right there. We put that through the whole hospital. You hear anything after Sam did the exorcism?_" he asked.

"He was…. It was here," Scully told him shakily, pushing herself to her feet. "It knew it was me and—."

"_You okay?_" Dean snapped.

"I'm fine," she breathed, walking over to the door and unlocking it. "Just…a little shaken up." The door swung open, revealing two doctors that swiftly came into the room. "I'll wait for you here," she told him.

Dean waited at Scully's side until the excitement had died down and the cover story spread of her having fallen into the corner of her desk, which had triggered Dr. Anderson getting dizzy and lightheaded from the stress of the long, intense shift he'd been on. Dean took a moment to explain briefly to Dr. Anderson exactly what had happened to him, assuring him that he would be okay, before handing him off to some other doctors. Once her wound had been bandaged and they were alone, sitting next to each other in folding chairs, Dean spoke up.

"I've got to know what happened," he told her softly. "I've got to make sure the exorcism worked on Pestilence cause we weren't sure it was going to. Did it leave Dr. Anderson before the exorcism was over?"

"Ah…no," she whispered. Scully took in and let out a deep breath. "No, I, um…. It was attacking me, trying to find out how I knew to use holy water, when the exorcism started. It tried to run but I used some of the holy water syringes to hurt it. I knew the water wouldn't hurt Dr. Anderson, so…."

Dean raised his eyebrows. "Nicely done."

Scully smiled briefly. "Thanks. Um…it was only at the end that it…that all the smoke came out and just…flew up and kind of…blasted away."

At that statement, Scully saw some of the tension in Dean's shoulders melt and he nodded. "That means it's gone," he told her. "The holy water with the treatments for the infected should keep working and it won't keep spreading now that the carrier's gone."

"That's…good news," she muttered.

"No kidding. Sam went to go meet Mulder outside and walk him over here. He's getting suited up and everything, but me and Sam didn't exactly have the time and we just kind of improvised our way in here so…" he said, letting his voice trail off.

"We'll run blood tests and make sure you guys didn't catch anything," she told him. "And me too."

"Okay." Suddenly Dean tensed again. "I'll need you to do the tests yourself."

Scully narrowed her eyes. "Why?"

"Um…there might be something in Sam's blood. Something different. I-I'm not sure what it would be, but…I wouldn't want anyone else seeing it," he told her tightly.

Scully stared at him for a moment, confused, before she simply nodded. "Okay. No problem."

"Thanks."

"Yeah. And thank you for…saving my life. All our lives. And, you know, not saying 'I told you so,'" she murmured.

Dean's expression shifted slightly into something Scully didn't quite recognize. If anything, she would have had to call it regret. "Not my place," he responded quietly.

Scully took a breath as if to say something, pausing before she spoke. "When you were on the phone with your friend…you mentioned…." Dean's face shifted once again, into an uneasy despair that he tried to cover up with a stiff coldness, and he averted his gaze. "And again now…Pestilence. A horseman. I mean, I thought it was just a code or a nickname or…. Dean," she whispered apprehensively. "I get the feeling that you've been exorcising demons for a long time. So you know what you're doing. This scared you too much to just be any demon."

Dean stared at a point on the other side of the room almost long enough for Scully to follow his gaze, thinking he was actually looking at something, before he spoke. "There's a war going on," he muttered. "Been in the makings for decades. And…this was just…one battle."

"A war," Scully whispered. "Against what?"

"Hell. Pretty much," Dean said softly, still looking away from Scully. "And everything that comes with it."

Scully suddenly noticed an almost subconscious iciness sliding through her. A horrible, disturbing dread that had crept up her back and into her chest. "Are we winning?" she forced herself to ask.

Dean finally raised his eyes to meet hers, his gaze filled with a heavy despondency and an incomprehensible hopelessness that Scully had rarely seen, especially in a man Dean's age. "No," he finally responded.

**THE END**


End file.
